1. Field of the Invention
The present invention relates to an image forming apparatus, and an image management method and an image management program performed in the image forming apparatus. More particularly, the present invention relates to an image forming apparatus connected to a network and comprising, for example, a function to add anti-counterfeit information an image management method and an image management program performed in that image forming apparatus.
2. Description of the Related Art
Recently, a copying machine which uses an electrophotographic technique has been widely spread and thus, a character or an image printed on paper and the like can be easily copied using the copying machine. Especially, a repro which is very hard to distinguish from an original can be easily formed using a recent color digital copying machine (MFP, for example). Therefore, it becomes important to take measures to prevent a printed material such as an important document from being counterfeited, falsified and illegally copied.
As the prevention measures against the counterfeit, the falsification, and the illegal copying, there is a method in which a latent image which cannot be recognized with eyes appears when some means and operation are applied to the printed material using a pattern comprising multiple geometric patterns as a design. Its representative example is a pattern such as a tint block, a guilloche pattern, a relief pattern and the like (referred to as the “tint block” hereinafter) widely used in printed securities. For example, when the document which is to be prevented from being copied such as an important document or a secret document is printed, a tint block comprising a latent image and a tint block pattern are combined therein. Since the latent image and the tint block pattern are printed at almost the same level of concentrations, the latent image cannot be recognized with eyes in this printed material. However, when this printed material is scanned by the copying machine, the tint pattern is erased by using a function of a base removing process such as a reading resolution limit of the scanner and as a result, the latent image such as characters like “copied material” appears in the outputted repro. Thus, although the latent image such as “copied material” is hidden in the original, when it is scanned, the tint block pattern is erased and the latent image appears, so that the original is distinguished from the copied material to prevent the information from being leaked or to track leakage of the information. The above technique is used in general.
Thus, when the anti-counterfeit information such as the tint block is combined with the image to be outputted, it is important that the anti-counterfeit information is hidden in the original and the anti-counterfeit effect appears at the time of scanning in view of security of the image. In order to implement the above, it is necessary to perform a process corresponding to the characteristics of the image forming apparatus which forms the original printed material. Thus, Japanese Unexamined Patent Publication No. 2002-77571 discloses a technique in which in a system comprising a first LAN having a server which manages data exchange with a database, and a second LAN having a terminal and a printer, the first and second LANs being connected through a communication line and the Internet, the server holds anti-counterfeit information such as the tint block corresponding to the output characteristics of each printer, and the anti-counterfeit information such as the tint block corresponding to the printer is combined at the time of printing by the printer and the like. In addition, Japanese Unexamined Patent Publication No. 2004-78752 discloses a printing control method implemented in a system in which a host device for an administrator and a host device for a user are connected through a network wherein the administrator determines whether a tint block is printed or not.
However, in order to make the tint block appear, a process which corresponds to the output characteristics of the copying machine is needed as described above. Therefore, when image information is transferred from an image forming apparatus to another image forming apparatus through the network, there is a case where anti-counterfeit information cannot be correctly formed in the other image forming apparatus.
In addition, according to the technique disclosed in Japanese Unexamined Patent Publication No. 2002-77571, since it is necessary to previously prepare and hold the anti-counterfeit information such as the tint block corresponding to the output characteristics of each printer, there is a problem that the device constitution becomes complicated. Similarly, according to the technique disclosed in Japanese Unexamined Patent Publication No. 2004-78752, when the printing instruction is given from the host device for the user to the printer, it is necessary to send inquiries to the host device for the administrator about the management information such as a host name, a user name and the like every time, so that there is a problem that the control becomes complicated.